Method of lowering the viscosity of liquids



UNITED STATES PATENT OFFICE.

METHOD OF LOWE-RING VISCOSITY OF LIQUIDS.

1,382,456. ll'o Drawing.

To'alZ whom it may concern:

Be it known that I, LINnoN W. BATES, a citizen of the United States, andresident of Mount Lebanon, in .the county of Columbia and State of NewYork, have invented a certain new and useful Improvement in Methods ofLowering the Viscosity of Liquids, of which the following is aspecification.

This invention pertains to a liquid fuel and to the process forproducing the same. More specifically it refers to a stable liquid fuelfor burning purposes, produced by the combination of oil or tar, orliquid or mobile fuels comprising oil or tar, with dehydrated water gastar or oil gas tar, which composite fuel possesses superior fuelqualities.

It is well known that many of the oils now used as fuel and tarssuitable as combustibles are of such hi h viscosity at normaltemperatures that t relatively short distances only, unless heated, andthat to be effectively atomized in existing burners they often have tobe preheated above their flash point. The heav oils from Mexico,Venezuela, Trinidad, and Sakhalin are especially subject to these disadvantages, which are usually even more accentuated when the oils havebeen topped, or the more volatile content partially or completelyremoved. For example, Standard oil from Mexico of specific gravity orrather density, 17.1- Baum, has a flash point in a Pensky-Martens closedcup of 145 F., and a viscosity of 300.5 Engler at 70 F. Another like oilhas a density of 15.4 Baum, flash point 202 F., viscosity 715 Engler at70 F. Certain Mexican residue has a density of 10 Baum, flash point of374 F., and viscosity of 67 Engler at 200 .F. A sample of Toltec oil hasa specific gravity of 11.7 Baum, flash point of 220 F. and viscosity of166 Engler at 125 F., while another sample of this oil shows 12 Baum,124 F., and 375 at 105 F., for density, flash point and viscosityrespectively. Richmond California oil has a density of 17.1 Baum, flashpoint of 228 F., and viscosity of 832 Engler at 70 F. Oil Burning Lt.Com. J. J. Hyland, U. S. N., Proceedings of the American Society ofNaval Engineers, 1914, vol. 26, p. 399 at p. 401). In orderto reducesuch heavy oils to the 815 Engler requlred for spraying, that is to sayatomization, 1n the present atomizers of liqu1d fuel a heatSpecification of Letters Patent. Application filed November 28, 1919.Serial No. 841,214.

ey can be pumped Engler not of the distillation of coal or of-as much as230 F. and over is frequently required. Such heating often exceeds theflash point, which is exceedingly dangerous ractice. (Eificiency in theuse of oil e1, Wadsworth, U. S. Interior Department Pamphlet, 1918, p.44).

he viscosity of liquid and mobile composite fuels having an oil base, isalso hi h and resembles that of the viscous oils escribed above. Thuswhen a light oil is combined with a bi h percentage of powdered coal orother carbonaceous substance stabilized therein, the viscosity of themixture closely approximates that of a heavy oil. On the other hand, theviscosity of a mixture of heavy oil with such powdered coal is notmaterially different from that of the heavy oil alone. Com osite fuelsof liquid hydrocarbon and pu verized carbonaceous substance duly treatedfor stability resemble in viscosity the heavy oils when the composite isin the liquid form and when ex tremely high percentages, such as over ofsolid carbons are used, the composites form pastes.

Endeavors have been made in the past to reduce the viscosity of heavyoils and to eliminate the consequential defects resulting therefrom. InGreat Britain for example, it is the practice to blend with the oils,other oils of lesser viscosity. In the United States, heavy oil isgenerally used as it comes and the viscosity is reduced by heat. In afew recent instances in this latter country, where alone the Burtonpressure stills are extensively used, pressure still oil or tar, soca1led, has been utilized as a, cutback or. blending liquid. The termpressure still oil or tar refers to the residual left after cracking aparafiin base oil in pressure stills. There is not a large amount ofthis liquid available and its price is higher than that of heavy oil. Ithas recently been suggested that naphthalene may also be used as acut-back, either alone or when dissolved with an oil itself derived fromoil produced from gas house coal tar, blast'furnace tar, coke-ovenby-product coal tar, or from petroleum, oil residue, or schist oil. Thepro- Patented June 21, 1921.-

8 5 Mex1can I alone or naphthalene combined with a prodoil. It is alsoknown in the art that middle fraction oils, such as creosote, andkerosene or hot wax tailings may be used. Kerosene, however, is at adisadvantage as a cut-back for asphaltic cipitate the asphaltic content.While technically suitable as cut-backs most of these liquids areeconomically unavailable. Thus to use refinable light oils is a waste ofnatural resources. Partially refined oils are not available in largequantities for the purposes in view and when of low viscosity areusually dearer than heavy oils. For these reasons, the reduction of thev1scos1ty of heavy oils and of liquid or mobile composite fuels by theaddition of liquids of low viscosity is not .as attractive commerciallyas it maybe made.

Chemical science, closed a cheap substance abundant in the United Statesand an easy way to reduce viscosity,'and hence to lower the temperatureat which asphaltic clots are formed and the necessary preheat to enablethe fuel to be atomized or sprayed. As a result of carefulinvestigation, it has been found that water gas tar and oil gas tar,either of these alone or together, when properly dehydrated and combinedwith the liquid. or mobile fuel whose viscosity. is to be reduced, willserve the purpose. As such tars when produced carry sometimes up to 40%of water, and often up to 30%, it is essential to dehydrate them so thatthe water content does not exceed about 10%. Dehydrated water and oilgas tars have a low viscosity. At 70 F. the viscosit of water gas tar isaround 427 Engler. ese two tars are respectively produced from thecracking of 011 vapors derived from treating coal and oil or oil alonewith superheated steam.

They are made in nearly all American gas plants, but not in all theBritish, where different systems of gas-producing are emploved. To makewater gas tar the bluegas from coal treated with steam is com- I binedwith gas oil, Oil gas tar is made from oil similarly cracked. (Asphaltsand Allied Substances, Abraham, 1918, p. 256 et seq.) They are broadlyand precisely distinguished by chemists from the tars produced by thedestructive distillation or partial combustion of coals or oils (same p.166, 262). Water gas tar and oil'gas tar are chemically different fromthe oils and tars heretofore used as cut-backs, such as pressure stilloil or tar, naphthalene, creosote, middle fraction oils generally andcoal tarsproduced in other ways. The ability of water or oil gas tar,when duly dehydrated, to reduce the viscosity of heavy oil or liquidcomposite fuels, to abolish the necessity of preheating many straightoils over their flash point, to form with the oil or com osite fuel astable liquid, and finally to re uce a composite paste to a liquid havebeen qualities heretofore unappreciated in this relation andcombinations not heretofore made.

The present invention consists, therefore,

base oils in that it tends to pre- ,from about 175 F. to 220 F of fromone to three hours. The heating indeed, has now dis-.

tank may be closed for safety if heatin above the flash point isrequired to blen the components and in the case of oils of low flashpoint less heat for a longer period may be employed. The treatment mayalso be given by passing the mixture through any suitable stirringmachine and heating the same during a 'tation. Agitation is preferablycombine with heat treatments where expedition is required, but eitheragitation or heat alone if sufficiently extended in duration and degree,will accomplish the result sought. The durationof the required as tar,or

treatment is necessarily variable, but must be such as will producethorough commingling. In general, the greater the heat within reasonablelimits and the more rapid the agitation, the less time is required tomix the liquids. The components may be mixed either in batches or bycontinuously pouring them together in proper proportions, using carefulcalibration. The water or oil gas tar may be combined with compositefuels during the blending of the components of the latter fuel or priorthereto. The methods mentioned are by way of illustration and notlimitation.

It is instructive to give certain examples of the reduction of viscosityby the use of dehydrated tar of the varieties mentioned, using the heatblending treatment described above. A typical tripped Mexican oil has aviscosity of 600 ngler at 70 F. The introduction therewith of 20% byweight of dehydrated water gas tar reduces the viacosity of the mixtureto 300 Engler, 40% to 68 En ler, 60% to 29.5 Engler and 80% to 23 ngler.At 160 F. the viscosity of the same 011 is 25.6 Engler and water gas taris 1 Engler. The use of 20% of dehydrated water gas tar reduces theviscosity of the composite at this temperature to 106 Engler which issufliciently low to allow proper atomization. The introduction of 40%reduces the viscosity to 427 Engler, 60% to 3.1 Engler and 80% to 2Engler. These tars are superior as cut-backs to the other liquidsavailable for this purpose. For example, at 160 F. 10% of ressure stilloil only lowers the viscosity of exican reduced oil from 25.6 Engler to18 Engler,

If while the same amount of dehydrated water gas tar lowers it to 13Engler.

The flash point of the same oil is 230 F While that of the dehydratedWater gas tar is 158 F. and of the composite is 194 F. when 20% ofdehydrated water as tar is used. A composite consisting o 60% oil 40%tar has a flash point of 189 F. and of 40% oil 60% tar has a flash pointof 185 F. and 20% oil 80% tar has 158 F. It may be noted from these datathat in the case of an 80% oil 20% tar composite, it is not necessary topreheat above the flash point to give adequate fluidity.

The stability of a mixture ofoil or composite fuel with water or oil gastar is adequate for all practical purposes. The two liquids form to someextent a true solution and to a considerable extent an emulsoid andemulsion of notable natural .stability. It must not be inferred,however, that all the ratios above stated can be used, and the fuelstill retain adequate stability. Up to about 28% water gas tar, 32% oiland 40% coal particles, by weight, may, for example, be-stably combinedfor over a month.

Having thus stated the nature of my invention, what I claim is:

1. A stable liquid fuel comprising liquid ydrocarbon and dehydrated tarobtained 3. A stable liquid fuel consisting of liquid or mobilecomposite fuel, viscous liquid hydrocarbon and pulverized carbonaceoussubstance, thinned by dehydrated tar obtained from the cracking of oilvapors derived from the treatment of coal and oil or oil alone withsteam.

4. That method of producing a stable liquid fuel which consists inadding dehydrated tar obtained from the cracking of oil vapors derivedfrom the treatment of coal and oil or oil alone with steam to a liquidor mobile composite fuel, including liquid hydrocarbon. and pulverizedcarbonaceous substance. and in heating the components together for aconsiderable time from 175 F. to 220 F.

commingle. ork city in the at a temperature of until they adequatelSigned at New county of New York and State of New York this 3rd day ofNovember, A. D. 1919.

LINDON WALLACE BATES.

